Reusable pouch type secondary battery, battery module comprising the same and method of reusing battery module

ABSTRACT

A pouch type secondary battery in which an electrode lead of the pouch type secondary battery and an electrode lead of an adjacent different pouch type secondary battery are welded together to construct a battery module is provided. The electrode lead of the pouch type secondary battery includes a length extended part so that, after cutting a welded part of the electrode leads of the pouch type secondary battery and the adjacent different pouch type secondary battery to form electrode leads of remaining length, the electrode leads of remaining length are welded together again. A battery module and method of reusing the battery module are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional of U.S. Application No.17/741,767, filed on May 11, 2022, which is a divisional of U.S.Application No. 16/338,228, filed on Mar. 29, 2019 (now U.S. Pat. No.11,362,389, issued on Jun. 14, 2022), which is a national phase entryunder 35 U.S.C. § 371 of International Patent Application No.PCT/KR2018/002006, filed on Feb. 19, 2018, which claims priority fromKorean Patent Application No. 10-2017-0052906, filed on Apr. 25, 2017,the disclosures of which are hereby incorporated herein by reference intheir entireties.

TECHNICAL FIELD

The present disclosure relates to a pouch type secondary battery, andmore particularly, to a reusable pouch type secondary battery and abattery module comprising the same.

BACKGROUND ART

Recently, with the dramatically increasing demand for portableelectronic products such as laptop computers, video cameras, mobilephones, and the like, along with the active development of electricvehicles, accumulators for energy storage, robots, satellites, and thelike, many studies of high-performance secondary batteries capable ofrepeatedly recharging has been conducted. Currently, among commerciallyavailable secondary batteries, lithium secondary batteries have littleor no memory effect, and thus they are gaining more attention thannickel-based secondary batteries for their advantages of freecharging/discharging, low self-discharging, and high energy density.

More recently, secondary batteries are being widely used in not onlysmall devices such as portable electronic products but also medium- andlarge-scale devices such as vehicles and energy storage systems (ESSs).In particular, with the steady exhaustion of carbon energy andincreasing interest in the environment, the demand for hybrid electricvehicles and electric vehicles is increasing all over the worldincluding United States, Europe, Japan, and the Republic of Korea. Insuch hybrid electric vehicles or electric vehicles, the most essentialcomponent is a battery pack that gives a driving power to an automobilemotor. Because hybrid electric vehicles or electric vehicles aresupplied with power for driving the vehicles throughcharging/discharging of battery packs, as compared to vehicles poweredby an engine alone, they have higher fuel efficiency and can eliminateor lessen the emission of pollutants, and by this reason, the number ofusers is now increasing.

When a secondary battery is used for an electric vehicle, to increasethe capacity and output, a battery pack is manufactured using batterymodules in which many secondary batteries are connected in series and/orin parallel. In this instance, pouch type secondary batteries are widelyused in medium- and large-scale devices because they are easy to stack.

FIG. 1 shows a general pouch type secondary battery.

Referring to FIG. 1 , the general pouch type secondary battery 1 has asealing part 30 formed by sealing a pouch case 10 in which an electrodeassembly 20 is received, and electrode leads 40, 45 are welded to apositive electrode tab and a negative electrode tab of the electrodeassembly 20 respectively and exposed through the pouch case 10. A leadfilm 50 is interposed between the pouch case 10 and the electrode leads40, 45. In the sealing part 30, particularly, a portion where theelectrode leads 40, 45 are drawn is called terrace T.

As shown in FIG. 2 , a plurality of pouch type secondary batteries 1 isstacked, and two adjacent pouch type secondary batteries 1 are connectedin series and/or in parallel such that the electrode leads 40, 45provided in each pouch type secondary battery 1 are connected to eachother to construct a battery module 11 with improved capacity andoutput. The reference numeral 60 is a structure that structurallysupports the battery module 11, such as a molded product.

When connecting the pouch type secondary batteries 1 to manufacture thebattery module 11, laser welding L is applied to connect the electrodeleads 40, 45. The battery module 11 is used for an automobile battery,and after the intended service life expires, it would be desirable thatthe battery module 11 is used for a second purpose, for example, an ESShaving less strict capacity retention rate or other conditions. To thisend, it is necessary to dissemble the existing connection structure ofthe first battery module and connect the pouch type secondary batteriesby a different method to manufacture a new battery module for thepurpose of reuse. However, conventionally, it was not easy to reusebecause it was impossible to separate the electrode leads 40, 45 joinedby laser welding L using a non-destructive method.

As in FIG. 3 , when a welded part A formed by laser welding L is cutalong a line C, the remaining electrode leads 40′, 45′ are too short. Bythis reason, it is impossible to reuse by reconnection and welding onlyusing the remaining electrode leads 40′, 45′.

As described above, conventionally, when disassembling a battery moduleand reusing pouch type secondary batteries for a new battery module,insufficient electrode lead length is problematic.

DISCLOSURE Technical Problem

The present disclosure is designed to solve the above-described problem,and therefore the present disclosure is directed to providing a reusablepouch type secondary battery.

The present disclosure is further directed to providing a reusablebattery module.

The present disclosure is further directed to providing a method ofreusing a battery module.

These and other objects and advantages of the present disclosure will beunderstood by the following description and will be apparent from theembodiments of the present disclosure. Further, it will be readilyunderstood that the objects and advantages of the present disclosure arerealized by the means set forth in the appended claims and combinationsthereof.

Technical Solution

To achieve the above-described object, a pouch type secondary batteryaccording to the present disclosure is a pouch type secondary battery inwhich an electrode lead of the pouch type secondary battery and anelectrode lead of an adjacent different pouch type secondary battery arewelded together to construct a battery module, and the electrode lead ofthe pouch type secondary battery includes a length extended part sothat, after cutting a welded part of the electrode leads of the pouchtype secondary battery and the adjacent different pouch type secondarybattery to form electrode leads of remaining length, the electrode leadsof remaining length are welded together again.

According to an embodiment of the present disclosure, the pouch typesecondary battery has a lead film between a pouch case and the electrodelead, and the lead film may include a surplus part so that the lead filmis formed to the length extended part. In this instance, the lead filmmay include a notch on two sides of a part of the lead film sticking outof the pouch case, the notches may be arranged to make the surplus partremovable from the length extended part.

According to another embodiment of the present disclosure, the pouchtype secondary battery further includes an insulation tape that coversthe length extended part. The insulation tape may be a composite film inwhich a PI or PP film has an adhesive layer.

To achieve another object, a battery module according to the presentdisclosure includes the pouch type secondary battery.

The battery module according to the present disclosure includes aplurality of stacked pouch type secondary batteries, each pouch typesecondary battery having an electrode lead including a length extendedpart, so that, after cutting a welded part of electrode leads ofadjacently pouch type secondary batteries to form electrode leads ofremaining length, the electrode leads of remaining length are weldedtogether again.

According to another embodiment of the present disclosure, each pouchtype secondary battery includes a terrace, and the electrode lead of thepouch type secondary battery included in the battery module is foldedinto the terrace of the pouch type secondary battery. The battery modulemay further include another insulation tape on a part where theelectrode lead is folded.

To achieve still another object, a method of reusing a battery moduleaccording to the present disclosure is a method of reusing the batterymodule according to the present disclosure.

An embodiment of the method of reusing a battery module according to thepresent disclosure is a method of reusing a battery module, in which aplurality of pouch type secondary batteries is stacked, each pouch typesecondary battery having an electrode lead including a length extendedpart, so that each electrode lead is capable of being cut after beingwelded to an adjacent electrode lead to form electrode leads ofremaining length, , and the electrode leads of adjacent pouch typesecondary batteries are welded together to form a welded part, the reusemethod including cutting the welded part of the battery module, andrearranging the pouch type secondary batteries and welding the electrodeleads of remaining length together to manufacture another batterymodule.

When each pouch type secondary battery has a lead film between a pouchcase and the electrode lead, the lead film includes a surplus part sothat the lead film is formed to the length extended part, and the leadfilm includes a notch on two sides of a part of the lead film stickingout of the pouch case, the notches being arranged to make the surpluspart removable from the long extended part, the reuse method may furtherinclude removing the surplus part before or after cutting the weldedpart of the battery module.

When each pouch type secondary battery further includes an insulationtape that covers the length extended part, the reuse method may furtherinclude removing the insulation tape before or after cutting the weldedpart of the battery module.

Another embodiment of a method of reusing a battery module according tothe present disclosure is a method of reusing a battery module, in whicha plurality of pouch type secondary batteries is stacked, each pouchtype secondary battery having a terrace and an electrode lead includinga length extended part, so that each electrode lead is capable of beingcut after being welded to an adjacent electrode lead to form electrodeleads of remaining length, each electrode leads is folded into theterrace of the pouch type secondary battery, and the electrode leads arewelded together to form a welded part, the reuse method includingcutting the welded part of the battery module, unfolding the foldedelectrode leads, and rearranging the pouch type secondary batteries andwelding the unfolded electrode leads together to manufacture anotherbattery module.

Further, the present disclosure proposes a method of reusing a generalbattery module. The reuse method is a method of reusing a batterymodule, in which a plurality of pouch type secondary batteries arestacked and electrode leads of adjacent pouch type secondary batteriesare welded together, the reuse method including cutting the welded partof the electrode leads to form electrode leads of remaining length,welding additional leads for electrode lead length extension to theelectrode leads of remaining length, respectively, and rearranging thepouch type secondary batteries and welding the additional leads togetherto manufacture another battery module.

Here, the step of welding additional leads for electrode lead lengthextension to the remaining electrode leads respectively is preferablyperformed by friction stir welding.

Advantageous Effects

According to the present disclosure, by solving the insufficientelectrode lead length problem when reusing pouch type secondarybatteries, a battery module of a new connection structure may beconstructed, no matter which connection structure is series or parallel.

According to an aspect of the present disclosure, it is possible toreuse the battery module through structure modification to increase theelectrode lead length of the pouch type secondary batteries. Because theremaining electrode lead length after cutting the joined part by laserwelding is enough long, the pouch type secondary batteries may be usedfor a second purpose after connected again.

According to another aspect of the present disclosure, it is possible toreuse a battery module including conventional pouch type secondarybatteries by joining additional leads to the battery module to extendthe electrode lead length, the battery module may be reused.

According to still another aspect of the present disclosure, while theelectrode lead length of the pouch type secondary batteries isincreased, the electrode leads are folded for space utilization. Thebattery module may be reused for a second purpose, for example, an ESS,by unfolding the folded electrode leads and changing the series/parallelconnection structure of the pouch type secondary batteries.

As above, according to the present disclosure, it is easy to reuse abattery module including pouch type secondary batteries, contributing tothe utilization of limited resources and maximizing cost efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate preferred embodiments of thepresent disclosure and together with the following detailed description,serve to provide further understanding of the technical aspects of thepresent disclosure, and thus, the present disclosure should not beconstrued as being limited to the drawings.

FIG. 1 is a schematic diagram showing a general pouch type secondarybattery.

FIG. 2 is a side view of a conventional battery module.

FIG. 3 is a diagram showing that it is difficult to reuse pouch typesecondary batteries in a conventional battery module.

FIG. 4 is a side view of a battery module including pouch type secondarybatteries according to an embodiment of the present disclosure.

FIG. 5 is a top view of a pouch type secondary battery according to anembodiment of the present disclosure.

FIG. 6 is a top view of a pouch type secondary battery according toanother embodiment of the present disclosure.

FIG. 7 is a side view illustrating a method of reusing a battery moduleincluding the pouch type secondary batteries shown in FIG. 5 .

FIG. 8 is a top view showing preparation before step (a) in FIG. 7 .

FIG. 9 is a side view illustrating a reuse method according to anotherembodiment of the present disclosure.

FIG. 10 is a side view of a battery module including pouch typesecondary batteries according to still another embodiment of the presentdisclosure.

FIG. 11 is a side view illustrating a method of reusing the batterymodule of FIG. 10 .

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the preferred embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings. Priorto the description, it should be understood that the terms or words usedin the specification and the appended claims should not be construed aslimited to general and dictionary meanings, but interpreted based on themeanings and concepts corresponding to the technical aspects of thepresent disclosure on the basis of the principle that the inventor isallowed to define terms appropriately for the best explanation.

Therefore, the embodiments described herein and illustrations shown inthe drawings are just a most preferred embodiment of the presentdisclosure, but not intended to fully describe the technical aspects ofthe present disclosure, so it should be understood that otherequivalents and modifications could be made thereto at the time theapplication was filed.

FIG. 4 is a side view of a battery module including pouch type secondarybatteries according to an embodiment of the present disclosure.

Referring to FIG. 4 , a plurality of pouch type secondary batteries 101is stacked, and two adjacent pouch type secondary batteries 101 areconnected in series and/or in parallel such that electrode leads 140,145 provided in each pouch type secondary battery 101 are connected toeach other to construct a battery module 111. The reference numeral 160is a structure that structurally supports the battery module 111, suchas a molded product, and the reference numeral 150 is a lead film. Theoutline of the pouch type secondary battery 101 is similar to that ofthe pouch type secondary battery 1 of FIG. 1 , and an electrode assemblyis received in a pouch case 110 and sealed to form a sealing part, andthe electrode leads 140, 145 are each welded to the positive electrodetab and the negative electrode tab of the electrode assembly and exposedthrough the pouch case 110. The lead film 150 is interposed between thepouch case 110 and the electrode lead 140, 145. A portion where theelectrode leads 140, 145 are drawn is called terrace T.

The electrode leads 140, 145 have the increased length compared to theelectrode leads 40, 45 of the conventional pouch type secondary battery1 described with reference to FIGS. 1 to 3 . The electrode leads 140,145 include a length extended part 141 so that the electrode leads ofthe remaining length after cutting a welded part A of the electrodeleads 140, 145 can be welded again. The size d of the length extendedpart 141 may be determined, taking into account a length that isdiscarded when cutting the welded part and a length and processingallowance required when newly welding, and when a currently used welderand the structure of the pouch type secondary battery are taken intoaccount, preferably the size of the length extended part 141 isapproximately 7 mm or more. When the length extended part d is smallerthan 7 mm or less, there is difficulty in aligning the welder to weldthe remaining parts after cutting the electrode leads 140, 145. When thelength extended part 141 is too large, the spatial volume of the batterymodule 111 increases due to the electrode leads 140, 145, and when theenergy density is considered, it is unfavorable. In view of thiscircumstance, the size d of the length extended part 141 is preferably 8mm or more and 15 mm or less.

The pouch type secondary battery 101 according to an embodiment of thepresent disclosure has the increased length of the electrode leads 140,145 compared to the conventional one, so that after use of the batterymodule 111, the pouch type secondary batteries 101 can be connected andreused by welding the remaining electrode lead parts after cutting thewelded part A of the electrode leads 140, 145. As described above, thepresent disclosure proposes manufacturing the pouch type secondarybattery 101 with the increased length of the electrode leads 140, 145compared to the conventional one, stacking the pouch type secondarybatteries 101, bending each electrode lead 140, 145, and joining theelectrode leads 140, 145 by laser welding L to manufacture the batterymodule 111. That is, the battery module 111 according to the presentdisclosure is manufactured by stacking the plurality of pouch typesecondary batteries 101 having the electrode leads 140, 145 includingthe length extended part 141 so that the electrode leads of theremaining length after cutting the welded part A of the electrode leads140, 145 can be welded again, and welding the electrode leads 140, 145of adjacent pouch type secondary batteries 101.

Because of including the length extended part 141, the battery modulewith the increased length of the electrode leads 140, 145 compared tothe conventional one has a short circuit problem in the event ofunwanted contact between the electrode leads 140, 145 with the increasedlength. The present disclosure ensures insulation by increasing thelength of the insulating film 150 to cover the length extended part 141.

FIG. 5 is a top view of the pouch type secondary battery according to anembodiment of the present disclosure.

To solve the insulation problem encountered when using the batterymodule 111 due to the electrode leads 140, 145 with the increasedlength, a surplus part 151 may be formed by increasing the length of thelead film 150 extending out from the pouch case 110 of the pouch typesecondary battery 101. The surplus part 151 may cover the lengthextended part 141. That is, an increase in the area in which theelectrode leads 140, 145 are covered by the lead film 150 ensuresinsulation. After the battery module 111 is used, the surplus part 151may be removed. To easily remove the surplus part 151, a notch N may beformed on two sides of the lead film 150. Instead of the notch N, aperforated line may be formed by punching, or a cutout corresponding tothe perforated line may be formed beforehand.

A plurality of notches N may be formed as shown, and only one notch Nmay be formed. The notch N may be in semicircular, circular, U or Vshape. The notch N may be included in two sides of the lead film 150extending out from the pouch case 110.

The lead film 150 may prevent a short circuit from occurring between theelectrode lead 140, 145 and a metal layer of the pouch case 110, as wellas improving the sealing of the pouch case 110. In the heat welding ofthe electrode leads 140, 145 made of metal and the pouch case 110 madeof polymer, the contact resistance is somewhat large, causing thesurface contact to reduce. However, as in the above embodiment, with thelead film 150, this contact reduction phenomenon may be prevented.Additionally, it is preferred that the lead film 150 is made of aninsulating material to prevent the application of the current from theelectrode leads 140, 145 to the pouch case 110. The lead film 150 isformed of a film with insulation and heat weldability. The lead film 150may be formed of, for example, a layer (a single layer or a multiplelayer) of at least one material selected from polyimide (PI),polypropylene (PP), polyethylene (PE) and polyethylene terephthalate(PET). In this embodiment, the lead film 150 serves to prevent a shortcircuit in exposed parts of the electrode leads 140, 145 through thepouch case 110 by increasing the length of the lead film 150.

The pouch type secondary battery 101 according to an embodiment of thepresent disclosure has an increase in the length of the electrode leads140, 145 and the length of the lead film 150, taking into account alength that is cut and removed when reusing and a length of a part to beadditionally welded, and the reusable battery module 111 includes thepouch type secondary battery 101.

FIG. 6 is a top view of the pouch type secondary battery according toanother embodiment of the present disclosure.

Referring to FIG. 6 , an additional insulation tape 155 is attached ontothe lead film 150 or the electrode leads 140, 145 extending out from thepouch case 110 of the pouch type secondary battery, ensuring insulationof the electrode leads 140, 145 with the increased length. Theinsulation tape 155 may cover the length extended part 141.Additionally, the insulation tape 155 may be PI or PP. Specifically, theinsulation tape 155 may be a composite film in which a PI or PP film hasan adhesive layer such as an epoxy adhesive. The additional insulationtape 155 provides an additional insulating portion to prevent apotential insulation problem caused by the long electrode leads 140,145. After use of the battery module 111, the insulation tape 155 (andeven a surplus part if the lead film has the surplus part) may beremoved. The insulation tape 155 may be removed from the electrode leads140, 145 through a simple operation of peeling off.

FIG. 7 is a side view illustrating a method of reusing a battery moduleincluding the pouch type secondary batteries shown in FIG. 5 . FIG. 8 isa top view showing preparation before step (a) in FIG. 7 .

The battery module 111 has a wide range of applications, and forexample, may be used as a power source for at least one medium- andlarge-scale device of power tools; electric cars including electricvehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybridelectric vehicles (PHEVs); electric truck; electric commercial vehicles;and energy storage systems. After the service life expires after use asintended, the battery module 111 may be reused through the reuse methodaccording to the present disclosure.

Referring to FIG. 7 , for reuse, first, the welded part A of theelectrode leads 140, 145 is cut along a line C from the conventionalbattery module 111 as shown in (a). In this instance, it may start withpreparation shown in FIG. 8 . That is, the surplus part 151 described inFIG. 5 or the insulation tape 155 described in FIG. 6 is removed first,leaving a lead film 150′ extending out from the pouch case 110 as muchas a normal length, and then step (a) of FIG. 7 may be performed. Thestep of removing the surplus part 151 described in FIG. 5 or theinsulation tape 155 described in FIG. 6 may be performed before or afterstep (a) or (b) of FIG. 7 .

After the welded part A is cut as shown in (a) of FIG. 7 , the pouchtype secondary batteries 101 are re-arranged as shown in (b), and asshown in (c), the remaining electrode leads 140′, 145′ are newly weldedL′ to each other to manufacture a different, new battery module 211.Specifically, after the remaining electrode leads 140′, 145′ are used asthey are and a new structure 165 is placed, the remaining electrodeleads 140′, 145′ are bent and welding L′ is performed with the bentparts brought into contact. Then, the pouch type secondary batteries 101may be re-arranged and re-constructed for reuse as a new battery module211.

Meanwhile, when the length of the electrode leads increases as describedin FIG. 4 , the space occupied by the electrode leads in the batterymodule increases in initial use, exerting negative influence such asarea ratio reduction. The size of the length extended part 141 may beselected, taking this area ratio into account as much as possible, butit will be more desirable if the battery module is reused withoutchanging the area ratio. The next embodiment relates to a method ofreusing a battery module without increasing the electrode lead length.

FIG. 9 is a side view illustrating a method of reusing a battery moduleaccording to another embodiment of the present disclosure.

(a) of FIG. 9 shows side view of a battery module including conventionalpouch type secondary batteries, for example, the general battery module11 such as that shown in FIG. 2 . After use of the battery module 11 asoriginally intended, the welded part A is cut along a line C into thestate of (b). The remaining electrode leads 40′, 45′ are too short touse as they are. The present disclosure proposes welding L‴ theadditional leads 41, 46 for electrode lead length extension to theremaining electrode leads 40′, 45′ respectively. After extending theelectrode lead length, referring to (c), for bending of the additionalleads 41, 46, placement of the structure 165 and construction of a newbattery module, welding L″ of the additional leads 41, 46 is performedto re-arrange and re-construct the pouch type secondary batteries 1 forreuse as a new battery module 311.

According to this embodiment, it is possible reuse the battery modulewithout increasing the length of the electrode leads at the initialmanufacture of the battery module. Rather, because a minimum length forwelding the additional leads after cutting the welded part is required,it is more preferable to increase the electrode lead length even alittle bit longer than those of commonly used general pouch typesecondary batteries. When welding L‴ the additional leads 41, 46 forelectrode lead length extension to the remaining electrode leads 40′,45′ respectively, many welding methods may be used, and when frictionstir welding is used, it is advantageous because the weld width is lessthan 1 mm.

The friction stir welding is a welding method that heats and softenstargets (in this embodiment, the additional leads 41, 46 and theremaining electrode leads 40′, 45′) by heat generated by friction byinserting a tool into the target and rotating the tool and stirring ofthe tool, leading to plastic flow, and welds the targets by the solidstate joining, for example, welds the targets together at the joinedarea. The friction stir welding is a method that joins the additionalleads 41, 46 and the remaining electrode leads 40′, 45′ in solid statewithout melting, and an advantage is that the characteristics of thewelded part are better than fusion welding.

FIG. 10 is a side view of a battery module including pouch typesecondary batteries according to still another embodiment of the presentdisclosure.

Referring to FIG. 10 , in the same way as the first embodiment, this isa case of increasing the electrode lead length for reuse by connectingthe pouch type secondary batteries with the remaining electrode leadpart after cutting the welded part after use of the battery module.

That is, the pouch type secondary battery 101 described with referenceto FIG. 4 is included in a battery module 121. The plurality of pouchtype secondary batteries 101 is stacked, and two adjacent pouch typesecondary batteries 101 are connected in series and/or in parallel suchthat the electrode leads 140, 145 provided in each pouch type secondarybattery 101 are connected to each other to construct a battery module121 with improved capacity and output. The reference numeral 160 is astructure that structurally supports the battery module 121, such as amolded product, in the same way as described previously.

The electrode leads 140, 145 are respectively welded to the positiveelectrode tab and the negative electrode tab of the electrode assemblyand exposed through the pouch case 110. A portion where the electrodeleads 140, 145 are drawn is called terrace T.

In this instance, this embodiment is characterized in that the lengthincreased electrode leads 140, 145 are folded into the terrace T of thepouch type secondary battery 101 to reduce the horizontal length. Toprevent a potential risk of a short circuit between the electrode leads140, 145 that are folded and overlap with the terrace T, an insulationensuring structure is needed, and is indicated by the reference numeral170 in the drawing. As described previously, the insulation ensuringstructure 170 may be formed by providing the length increased lead film150 having the surplus part 151 or the insulation tape 155 and foldingthe electrode leads 140, 145 neatly, and winding another insulating tapeafter folding the electrode leads 140, 145. The battery module 121 withthe structure of FIG. 10 may have a shape change or more complex shapeof counterpart (for example, a cartridge, etc.) for fixing the pouchtype secondary batteries 101 to fixedly receive the electrode leads 140,145 folded into the terrace T in overlapping manner, but preferablyensures spatial utility / insulation / secondary utility possibility.

FIG. 11 is a side view illustrating a method of reusing the batterymodule of FIG. 10 . After use of the battery module 121, the welded partA is cut along a line C as shown in (a), and the folded electrode leadsare unfolded as shown in (b). Subsequently, the electrode leads 140′,145′ are bent as shown in (c), and the structure 165 is placed and theelectrode leads 140′, 145′ are welded L″ to re-arrange and re-constructthe pouch type secondary batteries 101 for reuse as a new battery module211.

Of course, the methods of reusing by combining or applying thepreviously described embodiments are available. As described above,according to the present disclosure, the insufficient electrode leadlength problem encountered when reusing pouch type secondary batteriesis solved, and a battery module of a new connection structure may beconstructed irrespective of series/parallel connections structure.

As described above, the present disclosure proposes a method of reusinga battery module. The initial battery module is used, for example, as anelectric vehicle battery, and after the intended service life expires,may be manufactured into another battery module by rearranging andre-welding pouch type secondary batteries through the reuse methodproposed by the present disclosure. The newly manufactured batterymodule may be used for a second purpose, for example, an ESS having lessstrict capacity retention or other conditions than an electric vehiclebattery. As described above, according to the present disclosure, it ispossible to reuse without wasting the limited resources through thereuse of the battery module, and there are eco-friendly and costeffective advantages.

While the present disclosure has been hereinabove described with regardto a limited number of embodiments and drawings, the present disclosureis not limited thereto and it is obvious to those skilled in the artthat various modifications and changes may be made thereto within thetechnical aspects of the present disclosure and the equivalent scope ofthe appended claims.

What is claimed is:
 1. A battery module comprising: a plurality ofstacked pouch type secondary batteries, each pouch type secondarybattery having an electrode lead and a welded additional lead to providean electrode lead length extension, respectively; and wherein the weldedadditional leads of adjacent pouch type secondary batteries are weldedtogether.
 2. The battery module according to claim 1, wherein eachadditional lead is bent to have an “L” shape.
 3. The battery moduleaccording to claim 1, further comprising a molded structure locatedbetween the welded additional leads of the adjacent pouch type secondarybatteries.
 4. The battery module according to claim 3, wherein eachpouch type secondary battery has a terrace, and wherein the moldedstructure is overlapped by the terraces of the adjacent pouch typesecondary batteries.
 5. The battery module according to claim 1, whereinthe welded additional lead and the electrode lead are joined by a solidstate weld.
 6. The battery module according to claim 1, wherein thesolid state weld is formed by friction stir welding.